PROGRAMMING:Path geometry

In an mxn grid, an ant starts from the upper left corner, and its target is the lower right corner. There are only two directions: right or down. Please program to calculate the number of different paths from the upper left corner to the lower right corner. You can assume that the total number of paths is in the range of unsigned integers.
###Input sample 1:
Two positive integers separated by spaces, representing the number of rows and columns in a square.
```in
2 3
```
###Output sample 1:
Calculate and output the total number of different paths to the lower right corner.
There are three options:
1: Right, right, down.
2: Right, down, right.
3: Down, right, right.
```out
three
```
###Input sample 2:
Two positive integers separated by spaces, representing the number of rows and columns in a square.
```in
3 7
```
###Output sample 2:
Calculate and output the total number of different paths to the lower right corner.
```out
twenty-eight
```






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